Acceleration protective apparatus



Nov. 24, 1964 F. GRAY ACCELERATION PROTECTIVE APPARATUS Filed June 29,1959 AIR SOURCE ACCELERATION RESPONSIVE METERING MECHANISM ACCELERATIONRESPONSIVE VALVE so as to prevent anemia of the retina, or blackoutUnited States Patent 3,158,149 ACCELERATEON PROTECTIVE APPARATUS ReubenF. Gray, Levittown, Pa, assignor to the United States of America asrepresented by the Secretary of the Navy Filed June 29, 1959, Ser. No.823,786 4 Claims. (Cl. 128-1) (Granted under Title 35, U.S. Code (1952),see. 266) The invention described herein may be manufactured by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

The present invention relates to an acceleration protective apparatusand more particularly to an acceleration protective apparatus for use byan aviator subjected to accelerative forces of indefinite duration.

Various types of protective instrumentalities existing in the prior artare instrumental in mitigating with varying degrees of facility thedepletion of blood flow to the head during periods in which the pilot issubjected to accelerative forces such as those experienced in the divemaneuvers of an aircraft. A known device applies to the chest bladder ofa suit a pressure which is proportional to acceleration, such that theincreased hydrostatic pressure of the vascular system of the body duringperiods of centrifugal acceleration is substantially offset by theinternal pressure developed within the chest. During such periods it isa common practice for the pilot to hold his breath. For extended periodsof acceleration, the pilot, of course, cannot hold his breathindefinitely, and the continued application of an accelerativeresponsive pressure to the chest results in extreme discomfort to thepilot, manifested as so-called skin divers squeeze. Such mani festationoccurs because of the maintenance of a constant external pressure on thechest of the pilot during respiration.

Apropos of the restriction placed upon anti-blackout devices of theprior art, the instant invention includes the provision of a mechanismfor metering a discrete quantity of pressurized air to the chest sectionof a protective suit. As will hereinafter be set forth in greaterparticularity, the chest section comprising a pneumatically infiatablejacket, is inflated to a pressure corresponding to the accelerativelevel, and is thereupon effectively isolated from the pressurized airsource, so that the pressure within the jacket fluctuates as a directfunction of the pilots chest expansion and contraction. Hence, thediscomfort experienced by the pilot as skin divers squeeze is obviated,while the average pressure within the chest is sufiicient to combat theincreased hydrostatic head in the vascular system during extendedperiods of acceleration to thus prevent blackout.

An object of the present invention is the provision of a protective suitin which an external air pressure is applied to the chest in order todevelop a pressure within the chest for promoting blood flow to thehead.

Another object is to provide a protective suit in which an accelerationresponsive metering valve discretely controls the quantity ofpressurized air supplied to the jacket section of the suit so thatrespiration can be accomplished without personal discomfort to thepilot.

A further object of the invention is the provision of a protective suitin which the pressure within the jacket section thereof varies as afunction of the expansion and contraction of the pilot chest.

An additional object of the invention is the provision of a protectivesuit in which the initial pressure supplied to the jacket sectionthereof in discrete levels proportional to acceleration is varied as afunction of the expansion and contraction of the pilots chest, and thepressure ice within the trousers section thereof is maintained directlyproportional to the accelerative level.

The exact nature of this invention as well as other objects andadvantages thereof will be readily apparent from consideration of thefollowing specification relating to the annexed drawing in which:

FIG. 1 shows a schematic view in partial cross section of a preferredembodiment of the invention,

FIG. 2 illustrates a schematic side elevation view of the protectivesuit shown in partial cross section in FIG. 1, and

FIG. 3 is a diagrammatic view in partial cross section of theacceleration responsive metering mechanism of the invention.

Referring now to the drawings, wherein like reference charactersdesignate like or corresponding parts throughout the several views,there is shown in FIG. 1 a protective suit which comprises a jacket orchest section 11 and a trouser section 12. The inner portions 13 and 14of the suit are made preferably from a pliable waterproof material suchas rubber sheeting, rubber impregnated fabric, or the like, and readilyconform to the contour of the subject in a contiguous relationship. Theouter portions of the suit are made preferably from treated canvas, orother waterproof fabric, being characterized as flexible, butsubstantially inelastic. The sleeve member 17 illustrated in FIG. 2 issimilarly constructed and is attached to the chest section 11 as anintegral part thereof, forming the continuous closure 18. The inner andouter portions of the jacket including the sleeve member are joined bythermal bonding, adhesives, or the like. Not illustrated in the views ofFIGS. 1 and 2 are the various conventional tightening appendages formaintaining the protective suit in a fixedly secured position relativeto the pilot. Hoses 19 and 21 are attached in conventional manner to thejacket and trouser sections proper with the aid of couplers 22 and 23,respectively, as shown in FIG. 2.

The acceleration responsive metering valve 24 shown in block diagramform in FIG. 1 will be discussed with greater particularity inconnection with FIG. 3. This mechanism is coupled at the inlet side to ahose or conduit 27 and at the outlet side to hose id, supplying to thejacket section 11 of the protective suit a metered quantity ofpressurized air, which is proportional to acceleration. The accelerationresponsive valve 26 is conventional and may be of the type disclosed inthe patent issued to- T. Ferwerda, No. 2,760,484, for an Anti-BlackoutDevice, and through conduits 2i and 27 supplies to the trouser section12 of the protective suit a pressure which is directly proportional tothe accelerative level.

Referring next to FIG. 3, there is schematically illustrated in partialcross section the acceleration responsive metering mechanism of theinvention. An acceleration responsive valve 313 comprising member 311 ofgeneral cylindrical configuration having ports 34 and 4 8 is disposedfor movement within cylinder 32. A calibrated weight 33 is attached tothe acceleration responsive member 31 to impart to valve 30 properdisplacement characteristics. Annular lips 35 and 36 forming a part ofthe cylinder, fix the permissible limits of travel of the accelerationresponsive member 31. A compression spring 37 is interposed between thelower end of the member 31 and the bellows 39 over the stem 38, thelatter being attached to member 31 and slidably disposed within thecollar 60. The bellows is actuated by the air pressure of tube 41. Inresponse to an acceleration force directed vertically as in normalgravity, the member 31 is operably actuated so that the ports 34 and 40approach alignment with tubes 28 and 29, respectively.

Valve 42 deviates in its construction from valve 30 in that a singleport 43 is provided. A compression spring 44, the lower end of which isimmobilized, operably coacts with member 45 within cylinder 46 inopposition to the calibrated weight 47. The acceleration responsivemember 45, as in the previous instance, is operable to open or reducethe constriction in tube 28 with an increase in acceleration force. Thepurpose of valve 42 is to provide a linear relationship between thequantity of air supplied to the chest section of the suit and theapplied acceleration force.

The acceleration responsive valve 49 with bellows 51 functions toexhaust tubes M, 52, 53, 5d and 19 when the pilot is no longer subjectedto centrifugal acceleration forces. Displaceable member 54 having ports61 and 62 is connected at its upper end to a stem or rod 65, the latterbeing fixedly secured to a collar 66 which in turn is secured to bellows51. At its opposite end, member 54 is connected by a suitable projectionand retaining pin to lever 56, which is rotatable about a fixed pivot57. For purposes of adjustment, a Weighted member 58, which is slidablealong lever 56 and includes a set screw 59, is provided so that withgravity only, member 54 is operably resting against the annular lip 67of the cylinder 55. The exhaust outlets 63 and 6d are provided withsuitable constrictions, as illustrated, to introduce a suitableresistance to airflow for purpose of precluding abrupt exhausting.

The operation of the protective suit of the instant invention is bestdescribed in connection with the acceleration responsive meteringmechanism illustrated in FIG. 3. The regulated and pressurized air ofair source 25 is present in tube 27 and at the entrance to the valve 36by way of the bifurcated passage consisting of tubes 28 and 29.

During aircraft maneuver-s involving centrifugal accelerations operableto actuate valves 30 and 42, each of the slidable members 31 and 45 isdisplaced from the position illustrated in FIG. 3, according to themagnitude of the acceleration. Air pressure is admitted to tubes and 20,the former supplying air pressure to the jacket section 11 through thehose 19. The air pressure in tube .41 is modified by the accelerationresponsive valve 4-2,

the modified pressure causing bellows 39 to expand, compressing thespring 37 so that valve 36 closes. Thus, a metered quantity of air issupplied to the jacket section of the suit. A pressure proportional tothe acceleration is also present at this time in. tubes 52 and 53, butsince weight 58 is being subjected to the vertically directedacceleration, bellows 51 do not expand and valve 49 remains stationaryin the position illustrated. Thus, a metered quantity of pressurized airis supplied to the jacket section of the protective suit, the jacketefiectively being a closed system isolated from the air source 25. Thepressure within the jacket, therefore, will vary concomitantly withexpansion and contraction of the pilots chest. The average pressurewithin the jacket is suflicient at all times to offset the increasedhydrostatic pressure in the vascular system at the base of the lungsduring acceleration so that circulation is effectively maintained to thehead. For still higher accelerations the valve 3% admits more air to thechest section, and the bellows 39 respond to shut off valve 30, asbefore. Thus, the mechanism depicted in FIG. 3 is operable to supply tothe chest section a discrete quantity of air, such that duringacceleration intervals of indefinite duration, respiration of the pilotis accomplished without any manifestation of so-called skin diverssqueeze.

When the accelerative forces cease, valve 42 closes to the upwardposition, while valve 39, already closed, remains in the position, asshown. In addition, the pressure in bellows 51 is now sufiicient toovercome the force of weight 58 in the absence of acceleration, causingexpension of the bellows, which effects downward displacement of valvemember 54 so that the ports 61 and 62 align with the exhaust outlets c4and 63, respectively. The chest section is now effectively evacuatedalong with the line 41, relieving the bellows 39. When thepressurebetween exhaust outlet 63 and the line 53 is approximately equal, thevalve 49 assumes the position illustrated in FIG. 3. It should beunderstood that in the event the acceleration decreases from a higherlevel to a lower level, the acceleration responsive metering mechanismdepicted in FIG. 3 operates to release a discrete portion of air fromthe jacket through its associated exhaust outlet, and thereupon, themechanism is operably maintained in dynamic equilibrium at the loweraccelerative level.

The acceleration responsive valve 26 operates in a conventional mannerand supplies to the trousers section a pressure which is maintained at aconstant value proportional to t e accelerative level.

Hence, in the manner described, the protective suit of the instantinvention enables the pilot of an aircraft to breathe comfortablywithout any manifestation of skin divers squeeze during periods ofacceleration of indefinite duration. In addition, the application or" adiscrete quantity of air to the jacket section along with a constantpneumatic pressure to the trousers section of the protective suit as afunction of acceleration provides for an increase of pressure within thechest of the pilot so as to oflset the hydrostatic pressure in thevascular system. In this manner, the depletion of blood flow to the headis minimized.

While the acceleration responsive metering mechanism embodies a valve 39having two ports, it should be understood that a valve having a singleport may be used. In such modification, tube 28 is unnecessary, whiletube 20 would then be connected to tube 10. Furthermore, since valve 42pertorms a linearizing function, its incorportion is desirable but notmandatory.

It should be understood, of course, that the foregoing disclosurerelates to only a preferred embodiment of the invention and thatnumerous modifications or alterations may be made therein withoutdeparting from the spirit and the scope of the invention as set forth inthe appended claims.

What is claimed is:

1. In an acceleration protective apparatus including a source ofpressurized fluid and an inflatable jacket for providing an externalpressure to the chest of a subject, an acceleration responsive meteringmechanism comprising, valve means connected between the source ofpressurized fluid and the jacket, said valve means including adisplacement member operable in response to an accelerative level toadmit the flow of said fluid to the jacket, bellows means operablycoupled to said valve means for receiving said fluid and connected tothe displacement member so that actuation of the valve means in responseto the bellows means causes a quantity of fiuid to be timemetered to thejacket proportional to the accelerative level isolating thereupon thejacket from the pressurized source, and means including a bellowscoupled to the jacket and operable in response to the removal ofacceleration to exhaust the jacket.

2. Apparatus for protecting a subject against the adverse eftects ofacceleration comprising, a pneumatically inflatable jacket section, apneumatically inflatable trousers section, said jacket and trouserssections each being constructed of an inner substantially pliable memberadapted to conform in contiguous relation with the body contour of saidsubject and joined to an outer relatively flexible member having asubstantially unyielding characteristic, a pressurized source ofpneumatic fluid, means coupled with said pressurized source of'pneumaticfluid and said trousers section operable to supply a constant fluidpressure to the trousers section proportional to an accelerative level,and means coupled with said pressurized source of pneumatic fluid andsaid jacket section for operably admitting to the jacket section aquantity of said pneumatic fluid for a time interval solely proportionalto the acceleration and thereupon operable to close said jacket sectionto the entrance of additional fluid, whereby the fluid pressure Withinthe jacket section varies in accordance with the respiration of thesubject.

3. Apparatus for protecting a subject against the adverse eflects ofacceleration comprising, an inflatable jacket section includingintegrally formed inflatable sleeves, an inflatable trousers section,said trousers and said jacket sections including sleeves beingconstructed or" an inner substantially pliable member adapted to conformin contiguous relation with the body contour of said subject and anouter relatively flexible member having a substantially unyieldingcharacteristic, a pressurized source of fluid, means coupled With saidpressurized source of fluid and said trousers section operable to supplya constant fluid pressure to the trousers section proportional to anaccelerative level, and means coupled with said pressurized source offluid and said jacket section for operably admitting to the jacketsection including said sleeves a quantity of fluid for a time solelyproportional to the acceleration and thereupon operable to close thejacket to the entrance of additional fluid, Whereby the fluid pressurewithin the jacket section including said sleeves varies in accordancewith the respiration of the subject.

4. Apparatus for protecting a subject against adverse effects ofacceleration comprising, an inflatable jacket means adapted to providean external pressure to the chest of said subject, a pressurized sourceof fluid, acceleration responsive metering means coupled with saidpressurized source of fluid and the jacket means for operably meteringto the jacket means a quantity of fluid for a time interval proportionalto the acceleration, bel lows means coupled with said accelerationresponsive metering means to close the jacket means to the entrance ofadditional fluid, and bellows-actuated exhausting means coupled with thejacket means and operable in response to the removal of acceleration toexhaust the jacket means, whereby the fluid pressure within the jacketmeans varies in accordance with the respiration of the subject.

References Cited in the file of this patent UNITED STATES PATENTS2,228,115 Holste Ian. 7, 1941 2,335,474 Beall Nov. 1943 2,676,586Coakwell Apr. 27, 1954 2,760,484 Ferwerda Aug. 28, 1956 2,871,849Chatham Feb. 3, 1959 2,952,264 Burns Sept. 13, 1960

2. APPARATUS FOR PROTECTING A SUBJECT AGAINST THE ADVERSE EFFECTS OFACCELERATION COMPRISING, A PNEUMATICALLY INFLATABLE JACKET SECTION, APNEUMATICALLY INFLATATABLE TROUSERS SECTION, SAID JACKET AND TROUSERSSECTIONS EACH BEING CONSTRUCTED OF AN INNER SUBSTANTIALLY PLIABLE MEMBERADAPTED TO CONFORM IN CONTIGUOUS RELATION WITH THE BODY CONTOUR OF SAIDSUBJECT AND JOINED TO AN OUTER RELATIVELY FLEXIBLE MEMBER HAVING ASUBSTANTIALLY UNYIELDING CHARACTERISTIC, A PRESSURIZED SOURCE OFPNEUMATIC FLUID, MEANS COUPLED WITH SAID PRESSURIZED SOURCE OF PNEUMATICFLUID AND SAID TROUSERS SECTION OPERABLE TO SUPPLY A CONSTANT FLUIDPRESSURE TO THE TROUSERS SECTION PROPORTIONAL TO AN ACCELERATIVE LEVEL,AND MEANS COUPLED WITH SAID PRESSURIZED SOURCE OF PNEUMATIC FLUID ANDSAID JACKET SECTION FOR OPERABLY ADMITTING TO THE JACKET SECTION AQUANTITY OF SAID PNEUMATIC FLUID FOR A TIME INTERVAL SOLELY PROPORTIONALTO THE ACCELERATION AND THEREUPON OPERABLE TO CLOSE SAID JACKET SECTIONTO THE ENTRANCE OF ADDITIONAL FLUID, WHEREBY THE FLUID PRESSURE WITHINTHE JACKET SECTION VARIES IN ACCORDANCE WITH THE RESPIRATION OF THESUBJECT.